Process of manufacturing nitrogen compounds.



A. SCHWEITZER & P. HAUPF. PROCESS OF MANUFACTURING NITROGEN COMPOUNDS.

APPLICATION FILED MARJZ, 1912.

1,037,061 Patented Aug. 27, 1912.

- Fig.1. T

UNITED STATES PATENT OFFICE.

ALEXANDER sonwnrrznn AND rnrrz HAUFF, or sTU'rTeARr, GERMANY.

PROCESS OF MANUFACTURING- NI TROGEN .COMPOUNDS.

s ecification of Letters Patent.

Patented Aug. 27, 1912.

Application filed March 12, 1912. Serial No. 683,198.

To all whom it may concern:

Be it known that We, ALEXANDER SCHWEITZER and FRITZ HAUFF, citizens ofthe German. Empire; residing at Stuttgart, Germany, haveinvented-certain new and useful Improvements in Processes ofManufacturing Nitrogen Compounds, of which the following is aspecification.

Our invention relates to the manufacture .of nitrogen compounds byelectrically heat-- ing quantities of such substances as compounds ofthe alkalis or alkali earths in the presence of carbon and in anatmosphere of nitrogen.

Many processes of the above kind for the fixation of nitrogen, utilizingthe hydrates, oxids, or carbonates of the alkali or alkali earth metalsare known and patented, but when carried out on an industrial scalethese previous processes have been attended with great drawbacks. It hasbeen found ditficult and costly to attain the high temperature requiredfor the reaction and the retorts in which the reaction is carried outare seriously attacked owing to thebasic character of the charge.

The object of the present invention is to overcome the drawbackshitherto experienced and to secure a continuous operation.

The invention consists substantially in that the reaction charge, 2'. e.a mixture containing alkali or alkali earth metal compounds and carbon,is continuously guided through an electrically heated zone in a formallowing conductance of electric current and permeable to gas whenheated, in a direction opposing a current of nitrogen containing gas,the charge constituting'an v number of the lnsulating partitions 0 beingelectrical resistance in the heating zone.

To bring the charge to a form in which it can be used as a resistancefor conducting the electric current'the alkali or earth alkali compoundsalong with fluxes when required and coal are finely powdered and mixedand subjected t 0 a coking process, preferably after the mixture hasbeen formed into briquets. The mixture is thus in the form of lumpsand'incomparison with the uncoked mixture possesses increased electricalconductivity and a porous gas permeable structure which offers a largesurface very desirable in the treatment in a current of gas, whichporous condition is not lost when the briquets are subjected to theheat. Utilizing for instance a mixture containing equal proportions ofbarium carbonate and coal there is obtained a coke which isext-remely'suitable for forming the nitrogen compounds in an electricheating zone, and of which the composition corresponds with a mixture ofabout of barium carbonate and 40% of coke.

The continuous heating of any desired amount of the material formedin'the above described manner, forthe purpose of fixation of nitrogen,may be preferably carried out in a cupola furnace of the type illustrated in the accompanying drawings. ,At about half the height of'theshaft e of the furnace electrodes 6 pass transversely through the wallsa of the shaft and project into the charge space. To insure thatsubstantially only that part of the charge lying between the electrodesparticipates in the conduction of the current, the shaft is divided bypartitions terial arranged both above and below the electrodes andextending close to the zone between the same. The electrodes may be ofcarbon, graphite or the like but are preferably of chilled metal. Theremoval of the material takes place on the hearth of the furnace andfresh material is fed in to a corresponding extent at the top. Thenitrogen or gas containing nitrogen is blown in at the hearththroughpipes d and passes over the charge which is falling down throughthe shaft. The waste gases leave the furnace at f.

The furnace illustrated in the drawing is provided with two electrodes 6but there is no reason why a larger number should not be employed. Withpolyphase currents for example three electrodes may be used, the

then preferably such that there is one partition in the shaft at rightangles to the main direction of each current flowing through the charge.

What we claim is:

1. The process of manufacturing nitrogen compounds consisting incontinually guiding a mixture containing carbon and a compound of analkali or alkali earth metal through" an electrically heated zone, saidmixture being permeable to gas and possessing electrical conductivity,and itself serving as a resistance for the generation of heat,

preserving the permeability of the mixture during the heating operation,and passing a current of nitrogen containing gas through the materialwhile in the heated zone.

2. The process of manufacturing nitrogen compounds consisting incontinually guiding a mixture containing carbon and an-unfused compoundof an alkali or alkali earth metal through an electrically heated zone,

said mixture possessing electrical conductivity and itself serving as aresistance for the generation of heat, controlling such heat so as tokeep the temperature below the fusing point, and passing a current ofnitrogen containing gas through the material while in such electricallyheated zone. i

3. The process of manufacturing nitrogen compounds which consists informing a porous mixture of carbon and a compound of an alkali or alkaliearth metal, coking such mixture without fusion, guiding such cokedmixture through an electrically heated zone, the mixture itself servingas an-electrical conductor and resistance for the generation of heat,controlling such heat to prevent fusion, thereby preserving thepermeability of thematerial, and passing a current of nitrogencontaining gas through the mixture.

4. Process of manufacturing, nitrogen compounds consisting incontinually guiding a coked mixture containing alkali or alkali earthmetal compounds andcarbon through an electrically heated zone guiding acurrent of nitrogen containing gas through said mixture in saidelectrically heated zone and using said mixture as an electrical resistance in said heating zone and preventing the heating current frommaterially affect ing' the bulk of mixture outside the heating zone.

5. Process of manufacturing nitrogen compounds consisting in continuallyguiding a mixture containing alkali or alkali earth metal compounds andcarbon through a shaft provided with electrodes projecting thereinto,using the mixture within the shaft between the electrodes as heatingresistance in an electric current limiting the active zone of currenttransmission to that portion of the mixture lying substantially in theplane of the electrodes and transmitting a current of nitrogencontaining gas through said shaft .and mixture therein positionedbetween the electrodes.

6. Process of manufacturing nitrogen compounds consisting in continuallyguiding a coked mixture. containing alkali or alkali earth metalcompounds and carbon through a shaft provided with electrodes projectingthereinto, using the mixture within the shaft between the electrodes asheating resistance in an electric current limiting the active zone ofcurrent transmission to that portion of the mixture lying substantiallyin" the plane of the electrodes and transmitting a current of nitrogencontaining gas through said shaft and mixture therein in a directionopposite the direction of movement of the mixture through the shaft.

In testimony whereof, we aflix our signatures in presence of twowitnesses.

MLEXANDER SQHWEITZER. FRITZ HAUFF.

Witnesses:

Farm KLAIBER, PAULINE KLAIBER.

